Repeated and complete measurements from programs like Landsat allowed for the first time to better see and understand our planet as a whole. It became possible to use knowledge for environmental purposes. It made incremental and subtle changes visible, and helped us measure and adjust human impact on our environment wherever possible. A well-known example is the hole in the ozone layer over Antarctica, which was confirmed by satellite imagery in the mid-1980s. Regulations on emissions of harmful substances such as CFCs have led to a partial restoration of the ozone layer, a success which has also been recorded by satellites.
Satellites inherently have several limitations. It shouldn’t be too heavy, because it would take a lot of fuel to get it into space. There is always a risk associated with launches, as it was demonstrated again in November 2020, when a Spanish and French satellite was lost shortly after launch after the Vega launch vehicle veered off course. Once the satellite is in orbit, repairs can no longer be made. The right job must be achieved in one go and repeated endlessly.
One of the biggest advantages of satellites is their predictability. Satellites always do the same trick obediently, sometimes for decades. Some projects, such as the European Space Agency’s Copernicus, focus on the long term. As a satellite nears the end of its mission, an equivalent successor is launched. This leads to reliable and continuous measurements, says Earth scientist Richard de Joe, co-founder of Vandersat. He shared his academic career in entrepreneurship, out of a desire to bring images from space “closer to society.” His company processes satellite data into practical and up-to-date knowledge of value to its customers, including farmers, water companies, and insurance companies.
Most of the measurement data that Vandersat uses is publicly available. The trick is to combine multiple satellites to get a more accurate result. For example, during a drought, a farmer can use satellite data to determine where on his land he needs the most water, an increasingly common occurrence due to climate change.
Other satellite calculators have also dealt with topics from previous Earth days in recent years. “Trees for the earth” is a specialty of Satelligence, another Dutch company. Satelligence’s data system keeps traders in sustainable palm oil informed of deforestation activities, thus enabling them to choose good suppliers. On another topic, “Ending Plastic Pollution”, satellites may also provide a solution. A truckload of plastic waste ends up in the ocean every minute of the day, according to the 2020 World Economic Forum Report. Satellites can discover where this plastic has collected. Small pieces of plastic are hard to spot in satellite images and impossible to look underwater, but we can catch large floating currants from plastic sludge. Lauren Berman, a researcher at the Plymouth Maritime Laboratory, discovered a way to find plastic deposits called ocean basins on satellite images of the European Space Agency. She hopes this will lead to a global monitoring system. Now we need to mobilize a fleet of ships to clean up the mess.